At the urging of other members, I will diary the refurbishing of a 1960's GEM which I came by recently. It will be housed in an observatory and carry a 12" GSO (Ex Dob), but will retain the dob mounting plates (less bearing/tensioners) on the OTA so the unit can easily be dismounted and used as a Dob at another dark site. We roughly mounted the OTA today to check slew dimensions so observatory floor plans can commence. Several things came to mind, in particular, EP height. Observatory costs can be high, so if we reduce height, we reduce cost! Also, I don't want to be up large ladders when I turn 80! We intend firstly to replace the large saddle assembly and adaptor plate, which is better suited to a BBQ. A smaller adaptor plate and GSO alloy scope rings will be employed, reducing height by 3". Pier to be shortened by 10", (C/W still has clearance) and unsure yet to retain 3 large mounting feet, this would give us a height reduction of app 17" total. Any advice more than welcome!

Roger, As far as I know, the previous owner of the mount (for the past 40 years) got it from an engineer who constructed it in Arncliffe, NSW. The encoder on it was by a company which was bought out by Astronautical Instruments USA in 1964? So probably just a year or two prior to that.

Stepper motors, power supply and controller all wired and tested. (Bags of torque!) Motor mounts arrived, lathe organised for pulleys next week. awaiting PWM's for fine tuning, then a mock-up for final mounting. The beast almost lives!

Blew the backside out of the stepper controller, (actually set it on fire in the office!), so spent the weekend making/fitting manual brakes to both axis shafts for push-to use. Am trying to adapt clutch from old worm drive to fit to RA belt drive system. Waiting another month for replacement controller, if still experiencing problems, will build controller to suit EQASCOM from scratch and include a trial cooling system. ATM and DIY astronomy is definitely for the patient and persistent. Astronomy gear is now taking over my domicile, luckily no SWIMBO's to question the relevance of 24v power supplies on the kitchen table and parts waiting for paint to dry in the loungeroom in front of the fire.

Some considerable months have now passed, and interest has been rekindled. With the helpful assistance and advice of other IIS members from Canberra and Sydney, I have now opted for the more sensible and balanced version of a 10" SCT rather than the Newt, thus negating the risk of falling off stepladders when I've turned 80 and also having the joy of building a smaller obsy. My thanks to those people, and everybody else who has offered their learned opinions and prevented expensive mistakes. Motors to be mounted by the end of the month and hopefully all systems proven!